<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <script src="../react18/react.development.js"></script>
    <script src="../react18/react-dom.development.js"></script>
    <script src="../react18/babel.min.js"></script>
  </head>
  <body>
    <div id="app"></div>
    <script type="text/babel">
      class Child extends React.Component {
        render() {
          return (
            <div>
              <h2>Child组件</h2>
            </div>
          );
        }

        componentDidMount() {
          console.log("子组件重新渲染或者渲染", this);
        }

        //组件被卸载之前
        componentWillUnmount() {
          console.log("子组件被卸载");
        }
      }

      class App extends React.Component {
        state = {
          isShow: true,
        };
        render() {
          const { isShow } = this.state;
          return (
            <div>
              {isShow ? <Child /> : ""}
              <h2>App组件</h2>
              <button
                onClick={() => {
                  this.setState({ isShow: !isShow });
                }}
              >
                按钮
              </button>
            </div>
          );
        }
      }

      const root = ReactDOM.createRoot(document.getElementById("app"));
      console.log(root);
      root.render(<App />);
    </script>
  </body>
</html>
